1. Field of the Invention
This invention relates generally to a method of, and apparatus for, propulsion in a fluid, and more particularly for lifting and transporting loads and passengers with the principle of a rotary aeronautical lifting cell having a novel configuration of circular airfoil elements.
2. Description of Related Art
While the present invention relates to a propulsion device that can be used in a number of fluids, particular reference will be made throughout this disclosure to an air-type propulsion device for convenience of description only. When an airplane flies, it must first overcome two primary forcesxe2x80x94weight and drag. Weight is the force of gravity acting to pull the plane to the ground, which weight is overcome through lift. Lift enables the plane to rise into the air. Drag is created by the force of air particles striking and flowing around the airplane, and is overcome through thrust. Thrust is the push or pull on the plane that subjects the plane to a forward direction of travel. The thrust of an airplane is typically provided by jet engines or propellers.
The shape of a wing is what makes lift possible for an airplane. A wing incorporates a leading edge and a trailing edge. The leading edge slices through the air, producing two air streams, one over and one under the wing. Due to the curvature in the upper and/or lower surfaces of the wing, the upper air stream must travel faster over the top of the wing than does the lower air stream under the bottom of the wing in order for the two air streams to merge at the trailing edge of the wing at the same time. From Bernoulli""s Principle, when the velocity of air is increased, the air pressure in that region is decreased. Therefore, a wing has a lower pressure area directly over its upper curved surface than it does under its lower surface. This difference in pressures causes the higher air pressure underneath each wing to push the wing up into the air. This rising of the wing due to Bernoulli""s Principle is known as xe2x80x9cinduced lift.xe2x80x9d
Bernoulli""s Principle is also at work in a carburetor. Conventional carburetor devices produce a combustible fuel and air mixture by causing air to be drawn through a venturi into which liquid gasoline is fed. As the air passes through the venturi, the velocity of the air increases, which results in a drop in pressure of the air, providing a suction effect to pull in fuel.
Referring generally to an airfoil, an airfoil creates lift because the air stream encountered by the leading edge of the airfoil is split over and under the airfoil. The air adjacent the upper camber of the airfoil travels faster than the air adjacent the lower camber of the airfoil. The resulting pressure difference multiplied by the area of the wing defines the lifting capacities of the wing.
An airfoil shape works to generate lift because of the Coanda effect. At its broadest level, the Coanda phenomenon can be explained as the deflection of jets by solid surfaces. It is well known that flows have a tendency to become attached to or flow around a solid surface. The shape of the upper camber of an airfoil is designed to encourage adhesion of the air flowing over the top of the airfoil. The air flowing over the top of the airfoil adheres to the shape of the upper camber. This eliminates a certain amount of drag, and it also creates more lift. Also, as the air leaves the trailing edge of the top part of the airfoil, it has a downward direction. This provides another source of upward lift.
There are numerous disadvantages associated with conventional wings or helicopter rotors. A wing or rotor in an air mass must be moved forward in reference to the air mass in order to produce lift. Thus, a conventional airplane cannot operate as a helicopter, that is, land or takeoff vertically, due to the necessity of this forward movement. While the helicopter can takeoff and land vertically, the rotational velocity and the diameter of its rotors requires the helicopter to operate in an abundance of unobstructed air space so as to avoid contact with any obstacles.
Further, a helicopter rotor is susceptible to the development of cracks because of material conditions, including its narrow shape and length, and because of its operating conditions, including constant vibration, twisting and bending. A helicopter rotor also is relatively noisy because of the rotational velocity of the outer section of the blades, and the constant vibration encountered by the constantly changing directions of the air.
Thus, it can be seen that there is a need for a method and apparatus that can provide lift with the principle of a rotary aeronautical lifting cell, which cell overcomes the above identified disadvantages inherent in the conventional wing and rotor.
Briefly described, in a preferred form, the present invention presents both a novel method of propulsion, and a propulsion device, utilizing a rotary aeronautical lifting cell. In particular, the present invention relates to an aeronautical cell, or cells in tandem, and their use in flying machines. The aeronautical cell comprises a circular airfoil, a fluid propulsion system, a motive source and optionally a steering assembly.
The circular airfoil is an annular ring of an airfoil. The circular airfoil is defined by a bottom surface, which is preferably but not necessarily flat, an upper camber airfoil surface, and a center fluid intake hole.
The fluid propulsion device can aid in propelling the fluid over the airfoil. The fluid propulsion device can incorporate an airfoil divider extending upward from a portion of the airfoil surface. The airfoil divider also can extend through a portion of the airfoil via grooves in the airfoil. The airfoil divider generally is a wall separating the airfoil into airfoil sections. In this sense, the airfoil dividers are like vanes in a turbocharger.
The fluid propulsion device can alternatively incorporate vanes similar to those used on a xe2x80x9csquirrel cagexe2x80x9d type of blower wheel. These series of vanes can be located around the perimeter of the center fluid intake hole, or the outer perimeter, or a combination of both.
In another embodiment of the propulsion device, a combination of dividers and squirrel cage vanes can be used to propel the fluid over the airfoil.
The airfoil and dividers and/or vanes of the fluid propulsion device are sandwiched between a top and bottom element, which elements preferably lie in parallel planes. If the airfoil is separated into airfoil sections, the sections are arranged in a circular series, and are fixed atop a preferably rigid bottom element or circular bottom plate member. The airfoil does not extend from the bottom to the top element, so as to allow for airflow over the airfoil and under the top element. On the other hand, the dividers and/or vanes extend preferably normal between the bottom and top elements. Alternatively, either or both of the top and bottom elements can incorporate a dihedral angle to produce a more stable lifting cell. Dihedral is here defined as the upward angle given to all or part of the present cell. Dihedral is often used to provide roll stability, which is simply the tendency for an airfoil to level itself after some disturbance has banked it.
Air is forced to move above the upper camber airfoil surface of the airfoil by the fluid propulsion device and the rotation of the airfoil. In the embodiment incorporating the squirrel cage vanes, the angle of the vanes force the air over the upper camber airfoil surface in the same way a blower works in an air conditioning unit.
The bottom plate member can in turn be connected to a motive source to rotate the cell, for example, an output shaft of a motor confined within a motor housing.
In one embodiment, as each of the airfoil sections is moved through the fluid, for example, air or water, the fluid suctions through the center fluid intake hole, and is directed over the upper airfoil surfaces by the fluid propulsion device. Multiple cells of the present invention can be used in tandem or in series to increase the lifting capacity over just a single unit.
Thus, it is an object of the present invention to provide an improved method for propulsion.
Further, it is thus a general object of the present invention to provide a method of using a rotary airfoil and an apparatus for this novel airfoil.
These and other objects, features, and advantages of the present invention will become more apparent upon reading the following specification in conjunction with the accompanying drawing figures.